Place the tomatoes and onion in a blender or food processor and puree until smooth. Transfer 2 cups of the tomato mixture to a medium saucepan. Stir in the chicken stock, salt, and cumin and bring liquid to a boil over medium heat. (Reserve excess for another use, like Tomato Sauce.)

Meanwhile, heat the oil in a heavy Dutch oven over medium to medium-high heat. When the oil is sizzling, add the rice and sauté, stirring frequently until lightly toasted and golden, 8 to 10 minutes. Add the jalapeños and cook until they have softened, about 2 minutes, lowering the heat if necessary. Add garlic and cook for an additional 30 seconds.

I tilted the pan as much as I could and spooned out as much oil as I could at this point.

Pour the boiling tomato mixture over the rice and stir to combine. Turn heat to low and cook, covered, until liquid has evaporated and rice is done, about 15 minutes. Remove from heat and gently stir the rice. Re-cover the pot and allow to rest undisturbed for an additional 10 minutes.